While looking at your older car, you may have noticed a few areas on the body that have started to rust. Because the rust is detracting from the overall appearance of your vehicle, you may want to try to simply paint over the areas to hide the corrosion. However, there are a couple of reasons why you shouldn't just apply paint over the rust on your car's body.
1. Paint Will Bubble and Peel Sooner
One reason why you should not paint over the rust on your car's body is that the paint will not last very long. Since rust does not provide a solid, cohesive surface on which the paint can adhere, it will start to bubble and peel off sooner than other spots on the car.
Even if you were to apply a primer to the rusty surfaces before you start painting, the base coat will not stick securely. As the bonds between the rusted body, primer, and paint begin to weaken, the areas will become noticeable because of the flaking, peeling, and bubbling of the paint.
To ensure a more adhesive surface, you would need to thoroughly sand the body to remove the rust. However, if the rust is deep, the metal itself could crack or even break off. A professional who has worked with painting rusted car bodies would be better equipped at handling the job without causing permanent damage.
2. Rust Will Continue to Spread Underneath the New Paint
Another reason why you should not paint over rust is that the patch job would only be cosmetic. Since the rust would still be present, it would continue to eat away at the metal and spread underneath the paint.
Many people assume that applying a moisture-proof top coat on the paint will prevent the oxidation of the car body, however, this is not true. Instead, the rust continues to eat holes in the car body. Since it would be camouflaged by the paint, it's difficult to realize how severe the damage becomes.
If you have rusty areas on your car's body, the corrosion will continue to spread while the paint starts to come off, leading to even more rust. Instead of trying to paint over the problem areas in hopes that they will go away, take your vehicle to an auto body repair shop to have them assess the damage and discuss your options for getting rid of the rust before painting the body to a smooth, long-lasting finish. To learn more, visit an auto body shop near you.